This disclosure relates to pressure-relief vents. Vessels that contain pressurized fluid often include a relief valve that opens in response to a predefined pressurization condition in the vessel. While useful in practice, such valves can complicate testing and qualification of the vessel to meet minimum performance standards. For example, a vessel can be pressurized under controlled test conditions to ensure that it meets a given standard. However, since the valve is designed to open at a much lower pressure than the standard pressure against which the vessel is tested, the valve may be activated or compromised during the test, and also frustrate the objective of the testing.